Besides the strength and skills of the anticipants themselves, outdoor activities also require the outdoor sportswear be able to adapt to bad weather and complex geographical conditions in order to protect the personal safety of their owner. On account of the factors of sports and outdoors, the requirements for outdoor sportswear are comparatively more strict. In outdoor exercises, there exists much more heat and sweat produced, so the clothes must have good heat dissipation and drinking water vapor permeability; there'll be rainy, windy, snowy or foggy days in the open air, so the clothes must be water resistant.
The capability to resist h2o and to dissipate heat made by the body in the same time is hard to be obtained. Luckily, the sweat maded by body is drinking water vapor of single molecule state, while the rain and snow is liquid water drops in the state of aggregation. Volume of these two types of h2o differs a lot. Besides, liquid water has a characteristic called rod mill which happens to be the characteristic to aggregate itself in volume. If you mix a drop of detergent with a h2o drop, the drinking water drop will scatter flatly immediately because the detergent can lower its surface tension.
Sportswear of water-proof capability and water vapor permeability perfectly makes use of this characteristic of h2o, surface tension. It applies PTFE (same chemical component but different physical structure with Polytetrafluor ethylene, PTFE, best corrosion resistance) coating on the surface of the fabric to improve the surface tension of the fabric in order that the drinking water drops keep themselves together instead of scattering and infiltrating into the surface. In this way, h2o drops will not be able to go through the clothes. Meanwhile, this PTFE coating is porous so the water vapor of single molecule state can with success proceed through the tiny holes in the fabric and be dissipated to the surface of the clothes.
After large sum of movement, if we stop to rest in the rod mill, there may be water drops inside our clothes since it's cold outside and the sweat cannot be dissipated in time. It will make us feel not so comfortable. There may be a sort of film of polyurethane (PU) and nano-ceramic powder which is often coated on the surface of the fabric so to absorb the sweat vapor when we are sweating. This coating will refrain from the drinking water vapor inside the clothes from turning into water drops because the h2o vapor has exceeded the saturated vapor pressure.
Besides this characteristic, PTFE has other special functions. To illustrate, since PTFE has low-loss and small dielectric constant, PTFE film becomes the perfect insulation material to make capacitors, insulated cables and transformers. PTFE film is also one of many indispensible materials of making electronic components in aviation and space industry, etc. Many characteristics of PTFE make PTFE be commonly applied in countless fields like chemical engineering, petroleum, medicine, electronics and machinery.
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